Spinning-type fishing reels are well known in the art. A typical spinning reel comprises: a body structure; a mounting structure, extending from the top of the body structure, for mounting the reel beneath a fishing rod; a pinion sleeve rotatably mounted through the front end of the body structure; a rotor assembly secured to the forward end of the pinion sleeve; a main shaft slidably extending through the pinion sleeve and through the rotor assembly; a line spool secured on the forward end of the main shaft; a bail wire assembly attached to the rotor assembly for grasping a fishing line in order to wind the line around the line spool; a drive shaft extending laterally into the side of the body structure; a crank handle secured on the exterior end of the drive shaft; a drive gear (e.g., a face gear) mounted on the interior portion of the drive shaft; and an oscillation mechanism for imparting reciprocating movement to the main shaft and the line spool.
Typically, the drive gear meshes with a pinion gear (typically a helical gear) formed on the pinion sleeve such that, when the user turns the crank handle, rotational movement is imparted to the rotor assembly. As the rotor assembly rotates, the oscillation mechanism imparts reciprocating movement to the main shaft and the line spool. The reciprocating movement of the line spool ensures that the fishing line is properly wound over the width of the spool. The oscillation mechanism also prevents the main shaft and the line spool from rotating during the winding operation.
U.S. Pat. No. 5,316,239 discloses an oscillation mechanism comprising: a transmission member having a passage extending therethrough for receiving the rearward end of the reel's main shaft; a worm gear extending through the transmission member; an interior shaft keyed through the worm gear; an input gear (i.e., a helical gear) secured on one end of the interior shaft; a pawl held in the transmission member for operably engaging a continuous groove formed around the exterior of the worm gear; a guide rod extending through the transmission member; a cover plate positioned over the outer face of the transmission member for covering the pawl bore; and a bolt threadedly received in the transmission member and through the main shaft. The bolt holds the cover plate on the transmission member and secures the transmission member to the rearward end of the main shaft. The input gear meshes with the reel's pinion gear such that the worm gear is caused to rotate during the winding operation. As the worm gear rotates, the pawl follows the worm groove and thus causes the transmission member to reciprocate linearly along the worm gear. The transmission member, in turn, directly transmits this reciprocating movement to the main shaft and the line spool.
The guide rod employed in the U.S. Pat. No. 5,316,239 mechanism stabilizes the transmission member. As the transmission member reciprocates, the guide rod substantially prevents the transmission member from moving vertically and from moving laterally. Thus, the guide rod prevents excessive play between the worm shaft and the transmission assembly and helps ensure smooth, substantially wobble-free operation of the oscillation mechanism.
Unfortunately, the degree of precision and the amount of labor required for assembling the U.S. Pat. No. 5,316,239 mechanism are undesirably high. To assemble the mechanism, the main shaft and the guide rod must be inserted longitudinally into the reel body and then through enclosed passages formed in the transmission member. Further, the interior shaft of the worm assembly must also be inserted longitudinally into the reel body and then through the worm gear. Assembling the oscillation mechanism is thus time consuming and requires both a relatively high level of manual dexterity and precise alignment of the various components and passages employed in the mechanism.
In addition, to obtain adequate life, the transmission member employed in the U.S. Pat. No. 5,316,239 mechanism must be formed from stainless steel or from some other wear resistant material. As it reciprocates, the transmission member directly contacts and rubs against the guide rod. Thus, unless it is formed from a sufficiently wear resistant material, the transmission member must be frequently replaced. Forming the transmission member from such material can add significantly to the cost of the mechanism.